A. Field of the Invention
The present invention relates generally to optical fiber support apparatus and, more specifically, to apparatus for maintaining an optical fiber and a focusing means to direct light into a core of the fiber and to permit fine adjustment of a light beam directed into one end of the optical fiber core.
B. Description of the Prior Art
The use of optical fibers frequently requires that a beam of light having certain desirable characteristics be focused into the core of one end of an optical fiber. It is frequently very difficult to focus laser beams, for instance, into the core of a single-mode optical fiber in a reliable and stable manner. This need has led to the development, by others, of specialized optical fiber holders to maintain an end portion of optical fiber. The Newport Research Corporation (N.R.C.), for instance, has developed the FPH-S fiber holder to accommodate 4-8 mil single-mode fibers. The fiber holder is basically a cylindrical chuck provided with a radially extending slot to accommodate one end of an optical fiber. A leaf spring mechanism is required to maintain the fiber in a fixed position. The fiber holder and fiber may then be installed in a mount, for instance, the FP-1 mounting system of the FP-2 mounting system manufactured by N.R.C. Both mounts provide x-y-z movements; the FP-2 system provides angular positioning capabilities of the fiber as well. One problem with the mounting systems developed by N.R.C. is that a separate mounting system, for example an LP-1 or an LP-1B positioner, is required to position a focusing lens for directing a light beam into the core of the fiber. Thus, it is not possible to precisely maintain the end of an optical fiber and a focusing lens in a fixed relationship because of the lack of rigidity that results from using two separate mountings.
Another problem with prior-art, fiber-optic positioners, such as the type described above, is that, according to the manufacturer, the precision with which an optical fiber can be positioned is on the order of 200 microns or more. While such a limitation in precision may be acceptable for some fiber optics applications, in other applications, greater precision in the positioning of the optical fiber and the focusing lens is required. For example, in applications in which it is desired to direct a laser beam of light directly into the core of the single-mode optical fiber, it is desirable to be able to adjust the position of the optical fiber and the focusing lens in increments as small as one micron.
In view of the above limitations of prior-art focusing and mounting devices, it is an object of the present invention to provide a single mounting system for maintaining an optical fiber and a focusing lens in a precisely controlled relationship to one another.
Another object of the subject development is the provision of a means for adjusting the relative positions of one end of an otpical fiber and the focal point of a light beam by distances as small as one micron.
Yet another object of the subject development is to provide a means for positioning and maintaining a focusing lens near one end of an optical fiber that is relatively simple to use, that can be easily integrated with present-day technology, and that is inexpensive to manufacture.
The above objects are given by way of example; thus, desirable objectives and advantages achieved by the invention may occur to those skilled in the art. The scope of the invention is to be limited only by the appended claims.